1. Field of the Invention
The present invention relates to an information processing apparatus and method, a program, and an information processing system and method. More particularly, the invention relates to an information processing apparatus and method, a program, and an information processing system and method whereby QoS (Quality of Service) related control is provided in real time within each of end points as well as between these end points making up an entire network.
2. Description of the Related Art
FIG. 1 schematically shows a typical configuration of an ordinary AV (Audio and Video) system. The AV system in FIG. 1 is made up of pieces of business-use AV equipment such as MPEG IMX (Moving Picture Experts Group IMX) and HDCAM. More specifically, the representative AV system in FIG. 1 is constituted by such business-use AV devices as a video tape recorder (called simply as the VTR hereunder) 11, a monitor 12, another VTR 13, and a controller 14. AV data is transferred between these business-use AV devices over cables 21A through 21C dedicated to AV data transfer.
In addition to the AV data, the AV system of FIG. 1 has control commands such as RS-422 (9-Pin) commands communicated internally. If a 9-Pin command is issued and a response is not returned within 10 milliseconds, a communication error is recognized because the required levels of real-time performance are very high. The requirements are that certain processes be completed within a predetermined time period (i.e., predetermined time constraints must be met).
In order to meet the elevated requirements for real-time performance, the AV system of FIG. 1 utilizes control command cables 22A through 22C apart from the AV data transfer cables 21A through 21C. However, these two categories of cables being installed individually have led to problems associated with complicated wiring.
Hence the need for transmitting broadband data such as AV data and control commands over a single network cable in mixed fashion. The need is supposed to be met by suitable capabilities to ensure a maximum latency time in sending and receiving data including control commands, a process subject to exacting requirements for real-time performance.
To implement such capabilities illustratively involves resorting to Internet-ready priority control and quality support techniques. These techniques include Intserv and Diffserv. Intserv is a technique that envisages securing a frequency band between end points using a protocol called RSVP (Resource Reservation Protocol), thereby guaranteeing certain levels of quality of service (QoS). Intserv has yet to be commercialized because of the complexity of RSVP and other problems related to scalability and implementation of the technique. Diffserv is a technique used by routers on the network to schedule packets in accordance with the value of a DSCP field in an IP (Internet Protocol) header of each packet, thereby achieving a relative QoS guarantee.
The techniques outlined above involve control over end-to-end paths, not precedence-based control within an end point. That means it is impossible for these techniques to provide the latency time guarantee required by control commands.
An end point in this context refers to a section within a piece of AV equipment with a communication capability. An end-to-end path thus means a path between at least two different end points.
The inventors invented a technique for meeting required levels of real-time performance by speeding processes inside each end point. The invention is disclosed in Japanese Patent Laid-Open No. 2007-201884. The disclosed technique involves providing precedence control and frequency band control within each end point.